The proposed research begins with 500 randomly selected patients from a Universty Hospital Psychiatric Clinic who have already participated in research interviews. The objectives are: 1) To complete a family study of at least 1,000 first-degree relatives of the 500 index cases, and 2) to complete a six year follow-up study of the index patients themselves. Both the family and the follow-up studies will be conducted blindly; that is, without knowledge of index classification or illnesses. The goal of the study is clarification of the validity of psychiatric classification through assessment and comparison of index, follow-up, and family data. The purpose of follow- up studies is to determine whether marked differences in clinical outcome occur among patients similarly diagnosed. The absence of marked differences in outcome would be evidence of diagnostic validity (especially the absence of the appearance of new disorders). The purpose of family studies is to determine whether there are increased rates of prevalence of psychiatric disorders among the relatives of index patients. Increased rates of prevalence of the same disorder among relatives would be further evidence of diagnostic validity (independent of considerations of etiology).